Methods for ophthalmic devices incorporating metasurface elements

ABSTRACT

This invention describes Ophthalmic Devices with media inserts that have nanostructured Metasurface elements upon or within them. In some embodiments passive ophthalmic devices of various kinds may be formed. Methods and devices for active ophthalmic devices based on Metasurface structures may also be formed.

FIELD OF USE

This invention describes Ophthalmic Devices with media inserts andLenses that have Metasurface elements upon or within them.

BACKGROUND

Traditionally, an ophthalmic device, such as a contact lens, anintraocular lens, or a punctal plug, included a biocompatible devicewith a corrective, cosmetic, or therapeutic quality. A contact lens, forexample, may provide one or more of vision correcting functionality,cosmetic enhancement, and therapeutic effects. Each function is providedby a physical characteristic of the lens. A design incorporating arefractive quality into a lens may provide a vision corrective function.A pigment incorporated into the lens may provide a cosmetic enhancement.An active agent incorporated into a lens may provide a therapeuticfunctionality. Such physical characteristics are accomplished withoutthe lens entering into an energized state. A punctal plug hastraditionally been a passive device.

Novel ophthalmic devices based on energized and non-energized ophthalmicinserts have recently been described. These devices may use theenergization function to power active optical components.

Recently, it has been demonstrated that unique flat lenses may be formedby the fabrication of specialized surface structure having Nanoscalemetallic features arrayed on the surface. Various designs may be madethrough control of the Nanoscale feature's unit cell structure designs.

It may be useful to define ophthalmic devices to result from theincorporation of Nanoscale structures.

SUMMARY

Accordingly, the present invention includes a Media Insert with includedNanoscale metallic features that comprise a Metasurface. The Metasurfacemay be a repeating pattern of sub-wavelength sized features to aparticular wavelength of light. The interaction of the sub-wavelengthsized features may interact with the light and alter the phasecharacteristics of reemitted light from the features. The features inthis sense may also be considered Nanoscale antennas. There may benumerous methods to form Nanoscale metallic features on an insert andthese inserts may be encapsulated in a lens skirt of ophthalmic materialto form ophthalmic devices.

In some embodiments, an insert device may be defined by formingNanoscale metallic features into a periodic pattern across at least aportion of a surface of an insert device. The periodic pattern may havea length factor for the periodicity that is approximately equal or lessthan various wavelengths of visible light. In some embodiments, thedesign of the shape and size factors of the metallic features may bedetermined based on modeling a desired phase characteristic of theNanoscale features. Light that is incident upon the Metasurface elementsmay emerge with altered phase characteristics and this may be modeled.The design may be an ab-initio modeling process where the nature of thestructure, layout, feature location and other factors and the desiredeffect on light are used in a self-consistent model. Alternativelyiterative modeling based on trial designs with adjustments based onprevious results may be used. In some embodiments, the desired lenscharacteristics of the Nanoscale metallic surface may have a radiallysymmetric focusing lens characteristic. Models may generate desiredphase characteristics that have the radial symmetry and a focalcharacteristic of the effect of the collection of elements. When theinsert is formed to have a three dimensional and curved surface asopposed to a flat surface, there may be estimation protocols that may beuseful to transform the resulting lens characteristics of an Ophthalmicdevice with the Metasurface elements into a model of the Ophthalmicdevice in three dimensional space and the Metasurface as a equivalentflat space. There may be estimates to the effective focalcharacteristics of the Metasurface that may result in design parameters.The process may be used with the iterative modeling process as mentionedabove.

In some embodiments, the modeling processes may occur through the use ofsoftware based algorithms for which parameters may be provided by a userand which may be run on computing systems. The parameters that a userprovides may be based upon theoretical requirements. In other cases,Ophthalmic practitioners may measure the Ophthalmic characteristics andcorrective needs of a patient and formulate these needs into a set ofparameters for the modeling system. The computer systems may providenumerical output in some embodiments or provide spatially designedelements as arrays of design data points.

In some embodiments, preferably where the wavelength of the light is ina visible spectrum, the metallic features may have small surface areadimensions. As an example, the Metasurface features may have surfacearea dimensions that are 10,000 nm² or less. There might be muchdiversity in the periodic nature of the placement of the Metasurfaceelements. They might be deployed in rectilinear, polar or radialpatterns, or other periodic patterns. The spacing of nearest neighborsmay be related to the desired wavelengths of light to be interacted withby the elements. In some embodiments, this spacing may be less then orapproximately equal to the early red spectrum that may occur in thevisible spectrum. In some embodiments, the spacing or periodicity may beless then or approximately equal to 700 nm.

The insert may be enveloped in a lens skirt. A lens skirt may be made ofmaterials that are typically employed in the production of contactlenses, such as for example hydrogels. Molded into the ophthalmic skirtmay be stabilization features that may be useful to orient the lenswithin the eye. These features may be of particular use for Metasurfacelens elements that have high order correction aspects to them where thecorrection aspects are not radially symmetric. Various designs ofinserts may be employed which may fit into the resulting ophthalmicdevice. The overall shape of the surface of the insert that has theMetasurface elements upon it may be convex in nature or alternativelyconcave in nature. Other shapes that may be formed into inserts forophthalmic devices may also comprise art within the scope of thisdisclosure.

Active or non-static embodiments of the Metasurface elements may also beproduced. In some embodiments, metallic layers may be formed intofeatures that may be used under the influence of electrical energy toform or enhance the activity of Metasurface elements. The periodicityand shape aspects of the actively formed structures may be similar tothe discussions in the preceding sections. Electrowetting on Dielectric(EWOD) principles may be useful in some embodiments. One of theimmiscible fluids in an EWOD device may contain metallic nanospheres ormetallic nanorods. In some embodiments, the nanospheres or nanorods mayhave surface modifications to enhance their preference to one or anotherof the EWOD fluids. In some embodiments, the surface modification may becarried out by the chemical attachment of ligand molecules to theNanoscale metallic components. The surface of the insert whereMetasurface elements will be actively formed may have regions that havea preferred surface free energy to interact differentially with the EWODfluids. In some embodiments, the resting state of the EWOD regions maydefine a condition where the fluid containing the nanospheres, nanorodsor other shaped metallic constituents may be diffuse in space. By theapplication, of an electric field in the EWOD device the regionalpreference may be switched resulting in an accumulation of the fluidcontaining Nanoscale metallic constituents into shapes that compriseMetasurface elements.

Contact lenses may be formed which comprise inserts withthree-dimensional shapes to them where at least portions of the surfacesof the inserts may have static or active Metasurface elements upon themwhere the Metasurface elements have a lens effect. Some embodiments withactive Metasurface elements may comprise components that act with thephenomena of Electrowetting on Dielectrics. Within fluids of EWOD cellsmay be Nanoscale components that in some cases may comprise nanospheresor nanorods. Modification of the surface of the Nanoscale components inthe fluid may be performed in various manners and may include thechemical attachment of molecules to the surfaces of the Nanoscalecomponents to change their preference to one or more of theElectrowetting on Dielectric fluids. Embodiments with active Metasurfaceelements upon them may respond to an electric field that may becontrolled by other components located in the insert or within theophthalmic device. In some embodiments a variable focus contact lens mayresult from an electrically controllable formation of active surfaceMetasurface elements.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary embodiment of a Media Insert for anenergized ophthalmic device and an exemplary embodiment of an energizedOphthalmic Device.

FIG. 2 illustrates an exemplary contact lens with various featuresincluding an incorporated single piece insert that may be useful forimplementing aspects of the art herein.

FIG. 3 illustrates an exemplary alternative embodiment to thatdemonstrated in FIG. 2.

FIG. 4 illustrates an exemplary contact lens with various featuresincluding an incorporated multipiece insert that may be useful forimplementing aspects of the art herein.

FIG. 5 illustrates aspects of prior art related to a flat Metasurfaceelement based lens and to designing the Metasurface elements with ahyperboloidal phase profile to function as a lens.

FIG. 6 illustrates changes to the nanostructure modeling based on threedimensional lens substrates rather than flat substrates.

FIG. 7 Illustrates a phase characteristic estimation useful to model thelens.

FIG. 8 Illustrates an exemplary media insert comprising active elementsand Metasurface elements.

FIG. 9 Illustrates an exemplary active ophthalmic device with structuresthat introduce Metasurface elements upon activation.

FIG. 10 Illustrates an alternative exemplary active ophthalmic devicewith structures that introduce Metasurface elements upon activation.

FIG. 11 Illustrates exemplary methods for designing and formingOphthalmic devices with incorporated static Metasurface elements.

FIG. 12 Illustrates exemplary methods for designing and formingOphthalmic devices with incorporated dynamic Metasurface elements.

FIG. 13 Illustrates exemplary methods for utilizing Ophthalmic deviceswith incorporated dynamic Metasurface elements.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an ophthalmic device having Metasurfacecomponents that may affect changes in electromagnetic radiation in theenvironment of the eye. In the following sections detailed descriptionsof embodiments of the invention will be given. The description of bothpreferred and alternative embodiments are exemplary embodiments only,and it is understood that to those skilled in the art that variations,modifications and alterations may be apparent. It is therefore to beunderstood that said exemplary embodiments do not limit the scope of theunderlying invention.

GLOSSARY

In this description and claims directed to the presented invention,various terms may be used for which the following definitions willapply:

Energized: as used herein refers to the state of being able to supplyelectrical current to or to have electrical energy stored within.

Energy: as used herein refers to the capacity of a physical system to dowork. Many uses within this invention may relate to the said capacitybeing able to perform electrical actions in doing work.

Energy Source: as used herein refers to a device or layer that iscapable of supplying Energy or placing a logical or electrical device inan Energized state.

Energy Harvester: as used herein refers to a device capable ofextracting energy from the environment and converting it to electricalenergy.

Functionalized: as used herein refers to making a layer or device ableto perform a function including for example, energization, activation,or control.

Leakage: as used herein refers to unwanted loss of energy.

Lens or Ophthalmic Device: as used herein refers to any device thatresides in or on the eye. These devices may provide optical correction,may be cosmetic, or may provide functionality unrelated to the eye. Forexample, the term lens may refer to a contact lens, intraocular lens,overlay lens, ocular insert, optical insert, or other similar devicethrough which vision is corrected or modified, or through which eyephysiology is cosmetically enhanced (e.g. iris color) without impedingvision. Alternatively, the Lens may provide non-optic functions such as,for example, monitoring glucose or administrating medicine. In someembodiments, the preferred lenses of the invention are soft contactlenses are made from silicone elastomers or hydrogels, which include,for example, silicone hydrogels, and fluorohydrogels.

Lens-forming mixture or Reactive Mixture or Reactive Monomer Mixture(RMM): as used herein refers to a monomer or prepolymer material thatmay be cured and crosslinked or crosslinked to form an ophthalmic lens.Various embodiments may include lens-forming mixtures with one or moreadditives such as, for example, UV blockers, tints, photoinitiators orcatalysts, and other additives one might desire in an ophthalmic lensessuch as, contact or intraocular lenses.

Lens-forming Surface: as used herein refers to a surface that is used tomold a lens. In some embodiments, any such surface can have an opticalquality surface finish, which indicates that it is sufficiently smoothand formed so that a lens surface fashioned by the polymerization of alens forming material in contact with the molding surface is opticallyacceptable. Further, in some embodiments, the lens-forming surface canhave a geometry that is necessary to impart to the lens surface thedesired optical characteristics, including without limitation,spherical, aspherical and cylinder power, wave front aberrationcorrection, corneal topography correction and the like as well as anycombinations thereof.

Lithium Ion Cell: as used herein refers to an electrochemical cell whereLithium ions move through the cell to generate electrical energy. Thiselectrochemical cell, typically called a battery, may be reenergized orrecharged in its typical forms.

Media Insert: as used herein refers to an encapsulated insert that willbe included in an energized ophthalmic device. The energization elementsand circuitry may be incorporated in the Media Insert. The Media Insertdefines the primary purpose of the energized ophthalmic device. Forexample, in embodiments where the energized ophthalmic device allows theuser to adjust the optic power, the Media Insert may includeenergization elements that control a liquid meniscus portion in theOptical Zone. Alternatively, a Media Insert may be annular so that theOptical Zone is void of material. In such embodiments, the energizedfunction of the Lens may not be optic quality but may be, for example,monitoring glucose or administering medicine.

Metasurface: as used herein refers to man-made combinations ofNanoscaled features arrayed with periodicity. The combinations result inuseful characteristics that are distinct from natural structures. Inmany embodiments herein, the interaction of the features with light,particularly in a visible spectrum allow for lens devices to beconstructed.

Mold: as used herein refers to a rigid or semi-rigid object that may beused to form lenses from uncured formulations. Some preferred moldsinclude two mold parts forming a front curve mold part and a back curvemold part.

Nanoscale: as used herein refers to an element that has a feature orfeatures that has or have at least one dimension that is smaller thanapproximately 1 micron; thus its dimensionality for that at least onedimension may be referred to in nanometers.

Operating Mode: as used herein refers to a high current draw state wherethe current over a circuit allows the device to perform its primaryenergized function.

Optical Zone: as used herein refers to an area of an ophthalmic lensthrough which a wearer of the ophthalmic lens sees.

Power: as used herein refers to work done or energy transferred per unitof time.

Rechargeable or Re-energizable: as used herein refers to a capability ofbeing restored to a state with higher capacity to do work. Many useswithin this invention may relate to the capability of being restoredwith the ability to flow electrical current at a certain rate and for acertain, reestablished time period.

Reenergize or Recharge: as used herein refers to restoring to a statewith higher capacity to do work. Many uses within this invention mayrelate to restoring a device to the capability to flow electricalcurrent at a certain rate and for a certain, reestablished time period.

Reference: as use herein refers to a circuit which produces an, ideally,fixed and stable voltage or current output suitable for use in othercircuits. A reference may be derived from a bandgap, may be compensatedfor temperature, supply, and process variation, and may be tailoredspecifically to a particular application-specific integrated circuit(ASIC).

Released from a Mold: as used herein refers to a lens is eithercompletely separated from the mold, or is only loosely attached so thatit may be removed with mild agitation or pushed off with a swab.

Reset Function: as used herein refers to a self-triggering algorithmicmechanism to set a circuit to a specific predetermined state, including,for example, logic state or an energization state. A Reset Function mayinclude, for example, a power-on reset circuit, which may work inconjunction with the Switching Mechanism to ensure proper bring-up ofthe chip, both on initial connection to the power source and on wakeupfrom Storage Mode.

Sleep Mode or Standby Mode: as used herein refers to a low current drawstate of an energized device after the Switching Mechanism has beenclosed that allows for energy conservation when Operating Mode is notrequired.

Stacked: as used herein means to place at least two component layers inproximity to each other such that at least a portion of one surface ofone of the layers contacts a first surface of a second layer. In someembodiments, a film, whether for adhesion or other functions may residebetween the two layers that are in contact with each other through saidfilm.

Stacked Integrated Component Devices or SIC Devices: as used hereinrefers to the products of packaging technologies that assemble thinlayers of substrates that may contain electrical and electromechanicaldevices into operative-integrated devices by means of stacking at leasta portion of each layer upon each other. The layers may comprisecomponent devices of various types, materials, shapes, and sizes.Furthermore, the layers may be made of various device productiontechnologies to fit and assume various contours.

Storage Mode: as used herein refers to a state of a system comprisingelectronic components where a power source is supplying or is requiredto supply a minimal designed load current. This term is notinterchangeable with Standby Mode.

Substrate Insert: as used herein refers to a formable or rigid substratecapable of supporting an Energy Source within an ophthalmic lens. Insome embodiments, the Substrate insert also supports one or morecomponents.

Switching Mechanism: as used herein refers to a component integratedwith the circuit providing various levels of resistance that may beresponsive to an outside stimulus, which is independent of theophthalmic device.

Three-dimensional: as used herein refers to a shape or surface that isessentially not planar.

Energized Ophthalmic Device

Proceeding to FIG. 1, an exemplary embodiment of a Media Insert 100 foran energized ophthalmic device and a corresponding energized ophthalmicdevice 150 are illustrated. The Media Insert 100 may comprise an OpticalZone 120 that may or may not be functional to provide vision correction.Where the energized function of the ophthalmic device is unrelated tovision, the Optical Zone 120 of the Media Insert 100 may be void ofmaterial. In some embodiments, the Media Insert 100 may include aportion not in the Optical Zone 120 comprising a substrate 115incorporated with energization elements 110 and electronic components105. There may be numerous embodiments relating to including Metasurfaceelements into ophthalmic devices; however many may define surfaceportions within the Optical Zone 120 upon which Metasurface elements aredeployed.

In some embodiments, a power source 110, which may be, for example, abattery, and a load 105, which may be, for example, a semiconductor die,may be attached to the substrate 115. Conductive traces 125 and 130 mayelectrically interconnect the electronic components 105 and theenergization elements 110. The Media Insert 100 may be fullyencapsulated to protect and contain the energization elements, traces,and electronic components. In some embodiments, the encapsulatingmaterial may be semi-permeable, for example, to prevent specificsubstances, such as water, from entering the Media Insert 100 and toallow specific substances, such as ambient gasses or the byproducts ofreactions within energization elements, to penetrate or escape from theMedia Insert 100.

In some embodiments, the Media Insert 100 may be included in anophthalmic device 150, which may comprise a polymeric biocompatiblematerial. The ophthalmic device 150 may include a rigid center, softskirt design wherein a central rigid optical element comprises the MediaInsert 100. In some specific embodiments, the Media Insert 100 may be indirect contact with the atmosphere and the corneal surface on respectiveanterior and posterior surfaces, or alternatively, the Media Insert 100may be encapsulated in the ophthalmic device 150. The periphery 155 ofthe ophthalmic Lens 150 may be a soft skirt material, including, forexample, a hydrogel material.

The infrastructure of the media insert 100 and the ophthalmic device 150may provide an environment for numerous embodiments involvingnanostructured elements to form Metasurfaces. Some of these embodimentsmay involve purely passive function of the ophthalmic device, where forexample, the Metasurface component performs optical effects relating tovision correction for example. Other embodiments, may involve theophthalmic device having active functions where once again theMetasurface components themselves perform a passive function. Inaddition, in still further embodiments the Metasurface components maythemselves be part of the active function of the ophthalmic device.

Proceeding to FIG. 2, item 200 a depiction of an exemplary single pieceinsert may be illustrated in cross section. In FIG. 2, the ophthalmicdevice, 220, may have a cross sectional representation, 230, whichrepresents a cross section through the location represented by line 210.In an exemplary embodiment, the optic zone of the ophthalmic device 220may include a polarizing element, which may be represented in the crosssection as item 235. Upon the surface of item 235 may be nanostructuredelements to form the Metasurface. In other embodiments, item 235 maysolely represent a surface that has the Metasurface elements thereupon.Item 235 may represent a three dimensionally formed substrate which isattached to other insert forming pieces to form an insert.

As well, outside the optic zone of the device there may be printedpatterns placed on the single piece insert as shown by item 221 and incross section as items 231. In some embodiments, the insert piece maysimply comprise the Metasurface components at 235 and an optionallyprinted region at 231.

As shown in the cross section, the single piece insert piece 235 mayhave a three dimensional shape. For example, the piece may assume thethree dimensionally curved shape by thermoforming a thin sheet materialthat may start in a planar format. The Metasurface elements may be addedto the sheet either before or after this thermoforming is performed.

In some embodiments, there may be a requirement for orientation of theophthalmic lens within the ocular environment. Items 250 and 260 mayrepresent stabilization zone features that can aid in orienting theformed ophthalmic lens upon a user's eye. In addition, in someembodiments the use of stabilization features upon the single pieceinsert may allow for its orientation relative to the moldedstabilization features. The ability to orient may be particularlyimportant for placements of Metasurface features that are not radiallysymmetric in nature, as would be case for a pattern that may correctsecond order and higher aberrations in vision.

Proceeding to FIG. 3, item 300 a variation of the exemplary single pieceinsert shown in FIG. 2, may be illustrated in cross section. In FIG. 3,the ophthalmic device, 320, may have a cross sectional representation,330, which represents a cross section through the location representedby line 310. In an exemplary embodiment, the optic zone of theophthalmic device 320 may include a portion, not necessarily shown toscale in the figure, where the surface shape is concave to incidentradiation as opposed to the convex orientation. This may allow forembodiments, where instead of adjusting focusing aspects of theophthalmic lens the Metasurface elements may adjust divergent aspects ofthe lens surface. Upon this concave surface of item 335 may benanostructured elements to form the Metasurface. As well, outside theoptic zone of the device there may be printed patterns placed on thesingle piece insert as shown by item 331. In some embodiments, theinsert piece may simply comprise the Metasurface components at 335 andan optionally printed region at 331. For the same motivations as theembodiment in FIG. 2, there may be alignment features or stabilizationzones incorporated into ophthalmic device as shown as items 350 and 360,and there may be patterns printed upon the insert as features 331.

Proceeding to FIG. 4, item 400 additional embodiments where multi-pieceinserts may be used to form ophthalmic devices may be observed. In item405 a multi-piece insert 422 may include an active element in the opticzone. The figure depicts a cross sectional representation 430 acrossline 410. For exemplary purposes, the ophthalmic lens also includesprinted features as item 431, which may also be represented in crosssection as item 431. In addition, the exemplary lens may includestabilization features 450 and 460.

Multi-piece inserts may also be useful for embodiments with annularshapes where there is no insert material in the optical zone. WithMetasurfaces, a modification of this type of annular insert may be madewhere a two piece annular shape is found in regions depicted as item 436whereas a single piece of the insert may be located in the optical zoneand support the Metasurface elements.

An exemplary embodiment of a multipiece insert may include a meniscusbased active lens element at item 435 between the two insert pieces. Themeniscus lens may actively change focal characteristics when abattery-powered circuit applies electric potential across parts of themeniscus lens. Metasurface elements may also be included upon one of themultipiece surfaces. In a non-limiting example, the inclusion of passiveMetasurface focusing elements upon the surface of an active meniscuslens may allow for the adjustment of optical characteristics for higherorder corrective aspects of the lens.

The multipiece insert may include an active Nanoscale Metasurfaceembodiment as well. In subsequent sessions discussion is found for anembodiment that actively forms Metasurface elements within the regionbetween the two insert pieces at item 435. In some such embodiments, theoptical zone may have preferred orientations relative to the use's eyes.The methods used to form such a Metasurface including ophthalmic devicemay allow for registered alignment of the various components of the lensto the stabilization elements 450 and 460. These elements will thenmaintain an established orientation of the lens relative to the user'seyes.

Metasurface Lens Elements

Proceeding to FIG. 5, item 500 aspects of prior art implementations offlat surface based lens devices based on the phase altering interactionof light with Nanoscale metallic elements is displayed. In someimplementation of flat surface lenses, small metallic features may bedefined upon the flat surface in a design that interacts with light uponthe surface of the flat lens. In items 520 through 527 a set of designsof a functional lens are depicted. The features of 510 comprise the unitcell of Metasurface elements that are deployed across the flat surfacein such a manner to form a lens.

In an exemplary embodiment, the lens is optimized for wavelength around1.5 microns, a common communication electromagnetic wavelength out ofthe visual spectrum. In other embodiments, optimization may occur forwavelengths in the visual spectrum. The unit cell varies from item 520to 523. The length of the components ranges from 180 to 85 nanometers inlength, and as can be observed there is an angle between linear elementsof that length that ranges from approximately 90 angstroms to zero. Thethickness of the metal comprising the Metasurface devices may beapproximately 50 nanometers and devices may be separated from each otherby spacing ranging from 750 nanometers down to 200 nanometers. Whencloser than 200 nanometers, the Metasurface components may tend to“communicate” with each other and alter the properties of neighboringdevices. In the demonstration of functional devices, the number of unitcell components was made in four discrete steps although in practice thenumber of different component designs may be significantly more. Thevarious parameters relate to demonstrated practice for a certainwavelength range. Variation of the design aspects of the Metasurfaceelements in 510 including their thickness and lengths may be useful intuning the Metasurface elements to different wavelength ranges.

The depicted elements and the parameters mentioned above relate todesign aspects used to create a flat lens where the phase alteration ofthe Metasurface antenna elements is used to model a hyperboloidal radialphase distribution 590 that results in a lens. In 550, the importantelements relating to estimating the desired phase characteristic of anelement placed upon the flat lens 560 may be found. The lens 560 mayhave a radius as shown as item 561. The modeled lens may have a focallength characteristic shown as item 581. The modeled phasecharacteristics of a Metasurface element, for example 524, at position570 which may be represented as position (x,y), is such that the Phaseshift characteristic represented by item 590 is proportional to theprojection of the location vector upon the spherical model surface 580.That will result in the desired lens function with the desired focalcharacteristic 581. It can be demonstrated that for such parametricrelationships that such projection for the phase shift PS(x,y) willfollow the relationship of

$\begin{matrix}{{P\;{S( {x,y} )}} \cong {\frac{2\;\pi}{\lambda}( {\sqrt{( {x^{2} + y^{2}} ) + f^{2}} - f} )}} & (1)\end{matrix}$Where PS(x,y) represents the desired phase shift of a point x,y on theflat lens, and λ represents the wavelength of the light, and frepresents the focal characteristic of the lens desired. In a polarcoordinate system the phase shift PS(r, Θ) is

$\begin{matrix}{{P\;{S( {r,\Theta} )}} \cong {\frac{2\;\pi}{\lambda}( {\sqrt{r^{2} + f^{2}} - f} )}} & (2)\end{matrix}$

It may be apparent that incorporation of flat lenses of this type maycreate novel ophthalmic devices. In an intraocular device, a flatfocusing plane may be possible. Utilizing designs of this kind withinintraocular devices may be practical for adjusting focal characteristicsin a static sense. Alternatively, the active element embodimentsdiscussed in three dimensionally shaped devices in coming sections maylikewise have relevance for flat lens type intraocular embodiments.

Proceeding to FIG. 6, item 600 the resulting model for such a lenscondition where the surface is not flat may be depicted. It may bepractical to use similar unit cell designs for the Metasurface Nanoscaleelements as shown in 610 as items 620-627. Where the design aspects ofthe elements such as their thickness, angle of features and lengths maybe related to the desired central wavelength of focus and to thecalculated phase shift characteristics desired.

It may be apparent that switching from a flat lens to a curved lens mayintroduce additional complexity in modeling the device. The physicalphase characteristics to an incident plane wave based on the curvedsurface may introduce a first component of phase aspects of the device.In addition, now Metasurface elements may reside upon a globally curvedsurface that will change the angular orientation of the antenna featurein space. Furthermore, as the surface curves, the straight lineddistance between nanoshaped Metasurface elements and each other may bedifferent from the distance along the surface itself between elements.

There may be some reasonable estimation that may allow for estimatedlens design parameters. For example, to a first order it may be possibleto treat the phase characteristics of the curved surface, introducing aphase alteration of the plane wave interaction with the surface, and thephase altering characteristics of the Metasurface antenna elements asindependent. Thus to model the design parameters of the Metasurfaceantenna, it may be sufficient to consider the desired change of thephase due to the Metasurface antenna independent of the other phaseshift by subtracting that phase shift from the overall phase shift ofthe three dimensionally formed lens device.

In estimation, since the Nanoscale Metasurface antennas are so small itmay be a good estimate to model them as points. Although, there may bedifferences in how the plane wave interacts with a tilted NanoscaleMetasurface element, it may still be acceptable to ignore the impact byestimating the small device as a point that is not affected by thedistortion that curving the lens surface may introduce.

In addition, in another estimation the spacing between elements in thedesign may be estimated based on the distance between the elements in anon-curved space. In practice, the density of Nanoscale elements mayaffect the efficiency of the focusing device and a curved implementationmay decrease the density that Nanoscale elements may be placed at.Nevertheless, devices may still be created with first order effectswithin the estimate that the curved space does not limit the designdensity of Nanoscale elements.

The effect of curved space may be observed in the depiction of FIG. 6,item 690. A spherical model surface may be depicted as item 671. Acurved surface may be depicted as item 691 where a Nanoscale Metasurfaceelement such as item 624 may be located at a point on the surface (x′,y′, z′) at point 680. The resulting impact on the phase lengthcharacteristics may be observed as the shortened phase length 691. Theequations for estimating the phase shift may become equations whosedependence is three dimensional and represented by PS(x,y,z) oralternatively in a cylindrical coordinate system as PS(r, Θ, h).

Applying the various estimates mentioned, a method to apply the desiredoverall lens characteristics to a curved lens surface with Metasurfaceelements may be discussed in relationship to FIG. 7, item 700. In item710, a graphical depiction of the curved surface with Metasurfaceelements may be found. The combinational phase characteristics of thelens shape as item 730 and then the Metasurface component as item 740may be depicted. In an exemplary case where the Metasurface and thephysical curved surface are radially symmetric and focusing, adifference in focal length of the combined phase shifts may beunderstood as item 750, where item 760 may represent the resulting lensfocal characteristic as item 760. It may be a reasonable estimate tofocus on the relative construction angle of the two differentindependent focal characteristics where 770 may represent the angle ofthe Metasurface impacted focal characteristic on top of the physicalcurved lens surface focal characteristic.

Continuing with estimates, in 720 the case resulting if you decouple thephase shift characteristics of the curved ophthalmic lens device fromthe Metasurface device may be depicted. If the three dimensional impactof the total phase impact of the curved lens with Metasurface elementsis estimated to come entirely from the curved device phasecharacteristic, then it may be estimated that by subtracting thePSlens(x,y,z) phase characteristics across the lens surface you cantransform the desired Metasurface modeling condition to again match thatof a flat lens as discussed in reference to FIG. 6. This may be theequivalent of the cylindrical coordinate system having a representationwhere the height parameter—h is set to zero. If the resultingtransformation is estimated to occur by maintaining the focal lengthcontributions that may be modeled by maintaining the relative angles ofthe focal length characteristics as shown by item 771 then a newestimated focal characteristic for a transformed phase space flat lensmodel may be represented as item 750. Then the design aspects for suchMetasurface elements may be calculated in the same manner as mentionedrelating to FIG. 6, and equation 1, 2 where the “f” is now an estimatedeffective focal length from item 750. In practice more sophisticatedwavefront modeling systems may be used to rigorously calculated thedesired phase characteristics of arbitrary three dimensional curvedsurfaces and the resulting desired phase characteristics of NanoscaleMetasurface elements deployed thereon. For, making devices consistentwith the art herein, with estimated optical characteristics, the globalestimates may be applied.

In the estimated case where the cylindrical coordinates may becompressed to a polar coordinate relationship by the subtraction of thethree dimensional characteristics of the physical lens substrate thenthe polar coordinate phase representation may again be

$\begin{matrix}{{P\;{S( {r,\Theta} )}} \cong {\frac{2\;\pi}{\lambda}( {\sqrt{r^{2} + {f^{\prime}}^{2}} - f^{\prime}} )}} & (3)\end{matrix}$

Furthermore, the modeling of the design parameters of the individualMetasurface elements can be carried out with sophisticated modelingprotocols as for example Finite Difference Time-Dependent (FTDT)electromagnetic simulations. These simulations may be computationallyintensive if carried out on full three dimensionally deployednanosurface elements but possible. Alternatively the estimates discussedpreviously may provide an alternative to generate results that may beiteratively corrected through production, measurement and refinedestimation cycles.

Proceeding to FIG. 8, item 800, an exemplary embodiment of some of theconcepts may be found. Item 800 may represent an ophthalmic insertdevice that may be included within an ophthalmic lens in someembodiments, or represent an ophthalmic device on its own. The exampleincludes energization elements 830 that energize control circuitry 840that may comprise an integrated circuit. The integrated circuit as wellas other components may control other active components within thedevice. In a non-limiting example, in the active zone may be ameniscus-based lens capable of adjusting the optical power when lightproceeds through the device. Overlying this device in the optical zone,at 820 may be the Metasurface elements. In the magnified inset of 810,the Metasurface elements may be observed. These elements may be designedto provide a static optical correction that in combination with theactive change in optical power of the underlying lens element mayprovide novel function.

In some embodiments, as shown in FIG. 9, the Metasurface elements may bedefined in active manners as well. The exemplary meniscus lens discussedin item 800 may typically employ the technique of Electrowetting ondielectrics (EWOD). The technique acts on combinations of liquids bychanging the surface free energy of surfaces near the liquids.Combinations of immiscible liquids, where one liquid, for example is apolar liquid like an aqueous solution, and the other liquid is a nonpolar liquid like an oil may be effective for EWOD devices. Thetechnique may be used to create active creation of Metasurface elements.In item 910, a combination of EWOD type liquids without an appliedelectrical field across an active surface may result in a diffuse lenseffect without regularly defined Metasurface elements. The highlight of910 depicts a diffuse location of elements. These elements may be foundin the fluid layer identified as 915. In the inset, the fluid layer 915may be comprised of solvated components. In some embodiments thesecomponents may be metallic nanospheres such as shown by item 930 ormetallic nanorods as shown as item 935. The metallic components may becomprised of Gold, Silver, Platinum or other elements that can formnanosized components.

The surface of the nanocomponents may be coated with chemicals thatimpart a surface energy to the nanosized component. These coatedchemicals may establish a preference to certain fluid types or away fromcertain fluid types. The ligand molecules, 931 shown attached to thenanospheres 930 may in some embodiments make the nanospheres hydrophilicin nature or alternatively hydrophobic. If the nanospheres werehydrophilic they may be preferentially located in the aqueous componentof the EWOD liquid mixture. When the first liquid contains the nanosizedcomponents, like 915 in the depiction, the other component 913 may bedevoid of them. Then the fluids may be contained in microscalestructures that are surrounded by a top 912, side structures 911 and asurface layer 916 upon a dielectric 917. The surface layer may be suchthat the aqueous phase, for example, is preferred to wet across thesurface as shown by the contact of exemplary aqueous fluid layer 915across it. Underlying the dielectric 917 may be electrodes 918. Thefluid layers may be contacted by another electrode 914. When an electropotential is applied across the electrodes 918 and 914 the surface freeenergy at the surface of the surface layer 916 which is in the vicinityof electrodes 918 may change to favor wetting by the oil type layer(which may be considered an oil type wetting characteristic). Thiscondition may be depicted at 920.

If the electrodes are defined such that the nanostructure containingliquid when localized into smaller regions such as the case for liquid914 in the 920 case, then the nanospheres are concentrated into featuresthat may assume the nanosurface type designs as shown in the inset at920. These shapes would occur with concentrated nanometallic structurescomprised of nanospheres 930 or nanorods 935, which may interact withlight in similar fashions to the Metasurface components describedpreviously. The nanospheres or nanorods with attached surface moleculesmay be formulated to be a single size component within the mixture ofsize ranging from commercially available 2 nm-250 nm sphere sizes fromDiscovery Scientific Inc. Alternatively a combination of different sizesmay also be used. The optical properties of the fluids may be altereddepending on the size of sphere used or the combination of varioussizes. As well the ligands could play roles in interacting with theoptical properties by determining the closest spacing betweennanospheres in the liquid.

In some embodiments the side structure 911 may be designed to surroundindividual Metasurface elements. In other embodiments, multiple elementsmay be located within each isolated surface structure. The design of theelectrode locations 918, or missing electrode locations, may be madesuch that the individual elements are spaced at roughly 250 nm or moreapart. The relative surface area of the designed features 918 in theseindividual isolated cells may determine the relative amounts of the twoimmiscible fluids for containment of the design element of one fluidregion when the EWOD effect causes the definition of Metasurfaceelements.

Proceeding to FIG. 10, an alternative embodiment to that in FIG. 9 maybe found. Operating in a similar manner with Electrowetting as a meansof defining active Metasurface elements, the embodiment in FIG. 10,builds up the layer with nanostructured devices along the sidewall of anelectrode. At item 1010 the condition where the nanostructure containingliquid layer is located along the bottom of a small cell. The cell hassimilar structural features to that in embodiment 900. Item 1011 may besidewalls containing the micro-fluidic cell. A top of the cell may beitem 1012. Item 1014 may be an electrode formed in the desired shape ofa nanosurface element. Item 1013 may be a dielectric film formed on thesidewall of the electrode that has the desired wetting properties on itsside. Item 1015 may be an electrode that penetrates through the top ofthe cell. Item 1016 may be the fluid layer containing the solvatednanospheres and item 1018 may be the other fluid layer. The layer 1016may have the similar metallic nanospheres 930 and nanorods 935, whichmay have attached ligand molecules 931 to define the surface free energyof the nanostructure and therefore which liquid type it would prefer tobe solvated within.

When an electric field is applied across electrode 1015 and electrode1016, this applied potential may change the surface free energy of thesidewall region of item 1016 causing the fluid layer 1016 to move alongthe sidewall region as shown in the depiction related to 1020. Theaccumulation of the fluid in the region may form the Metasurfacestructures as shown in item 1020. Again, the application of voltageacross the cells may generate an active nanostructure pattern that mayhave the modeled optical effects. In some embodiments, the applicationof the voltage may be controlled by the electronics contained within aninsert structure that also contains energization elements.

The resulting Metasurface structures that are created in the embodimentof item 1020 where they are located in the proximity of the metalelectrode may have altered optical interaction because the structure ofmetal nanostructures with a dielectric and a second metal structure maycreate nanostructures with couple more strongly with the magnetic fieldof the electromagnetic radiation. This may create additional wavelengthbased resonances based on parameters such as the thickness of thedielectric film. This may create another dimension for the modeling ofthe nanosurface structures incorporated into such embodiments.

Methods

Proceeding to FIG. 11, item 1100, exemplary methods of designing andforming ophthalmic devices which include Metasurface elements may befound. At 1101 a model for an ophthalmic device may be formed. The modelmay comprise a three dimensional substrate form which may have at leasttwo important aspects. First, the substrate form will typically define ashape of a conventional ophthalmic device which may understood opticalproperties, which also may be represented as point based phasecharacteristics imparted to incident light. Second, upon the shape orwithin the shape a network or array of three dimensionally deployedNanoscaled metallic elements may be layed out. The system may be used bysophisticated modeling systems that model the wavefront characteristicsof the optic elements and the nature of the electromagnetic interactionwith the Nanoscale Metasurface elements. In other simplified estimates,the model may be broken down into a standard device lens characteristicsand a superimposed Metasurface lens which may be estimated to functionas a flat Metasurface lens. Regardless of the modeling approach, desiredophthalmic parameters may be fed into the modeling system along withempirical results as appropriate to generate the design aspect of boththe substrate shape as well as the individual nanosurface elementdesigns across that shape.

Proceeding to 1102, the model information may be used to fabricateNanoscale Metasurface antenna elements upon a substrate. In anon-limiting example, this process may first involve placing Metasurfaceelements upon a flat substrate and then forming the substrate into adesired three dimensional shape. For example, the forming of the flatsubstrate may be carried out by thermoforming. In order to place theMetasurface elements there may be numerous methods that can yield thedesired result. A thermoformable substrate may be coated with a thinfilm of chemical resist as may be used in the semiconductor industry.Then, for example, a nanoimprint lithography substrate may be used toimpress into the photoresist the pattern desired for the Metasurfaceelements. The nanoimprint substrate may be as large as the desiredophthalmic substrate or alternatively it may contain multiple versionsof the desired ophthalmic substrate pattern. In some embodiments it maybe possible to step the nanoimprint substrate multiple times across theophthalmic substrate to transfer the appropriate pattern.

Again, as a non-limiting example, recesses into the thermoformablesubstrates may be etched by either a chemical etch or a reactive ionetching technique. A film of metal, typically comprising Gold, silver,platinum or copper or other metallic component or alloy may be depositedupon the substrate with etched features and photoresist. A lift-offprocess may next remove metal and photoresist leaving a pattern ofnanostructured features. Chemical cleans and physical polishing stepsmay be useful to remove material remaining of the photoresist or metallayer.

At 1103, the resulting substrate may be transformed into a threedimensionally shaped feature. In some embodiments this may be performedby thermoforming the substrate. The resulting three dimensional shapemay become a part of an insert or may be an insert in its own right.Next at 1104, an insert with the Nanoscale metallic features may beplaced into a mold form. The insert, at 1105, may then be surrounded byophthalmic material which may be called reactive mixture andencapsulated as ophthalmic material may be polymerized and shaped withthe mold around the insert. When removed from the mold a form of anophthalmic device may be obtained. At 1106, the resulting ophthalmicdevice may be measured for its optical characteristics for example by awave front aberrometer. Results from the measurement may be used todetermine if the device thus formed is acceptable. Alternatively, at1107 an alternative model may be formed by adjusting parameters in themodeling system based on the measured results. At 1108, these adjustedparameters and modeling characteristics may be feed back for refinementof the lens design.

Proceeding to FIG. 12, item 1200, exemplary methods of designing andforming ophthalmic devices which include active Metasurface elements maybe found. The flow is similar to that discussed in reference to FIG. 11.At 1201 a model for an ophthalmic device may be formed. The model maycomprise a three dimensional substrate form which may have at least twoimportant aspects. First, the substrate form will typically define ashape of a conventional ophthalmic device which may understood opticalproperties, which also may be represented as point based phasecharacteristics imparted to incident light. Second, upon the shape orwithin the shape a network or array of three dimensionally deployedNanoscale forming features may be laid out. As discussed in previoussections these forming features may cause Metasurface elements to formunder the action of electric potentials. The resulting designed systemmay be used by sophisticated modeling systems that model the wavefrontcharacteristics of the optic elements and the nature of theelectromagnetic interaction with the Nanoscale Metasurface elements thatwould form actively. In other simplified estimates, the model may bebroken down into a standard device lens characteristics and asuperimposed Metasurface lens which may be estimated to function as aflat Metasurface lens and the complex active elements that may becollections of nanoparticles in a suspension in a fluid may be estimatedas solid metallic features. Regardless of the modeling approach, desiredophthalmic parameters may be fed into the modeling system along withempirical results as appropriate to generate the design aspect of boththe substrate shape as well as the individual nanosurface elementdesigns across that shape.

Proceeding to 1202, the model information may be used to fabricateNanoscale Metasurface antenna forming elements upon a substrate. In anon-limiting example, this process may first involve placing Metasurfacecontrolling elements upon a flat substrate and then forming thesubstrate into a desired three dimensional shape. For example, theforming of the flat substrate may be carried out by thermoforming. Inorder to place the Metasurface controlling elements there may benumerous methods that can yield the desired result. A thermoformablesubstrate may be coated with a thin film of chemical resist as may beused in the semiconductor industry. Then, for example, a nanoimprintlithography substrate may be used to impress into the photoresist thepattern desired for the Metasurface elements. The nanoimprint substratemay be as large as the desired ophthalmic substrate or alternatively itmay contain multiple versions of the desired ophthalmic substratepattern. In some embodiments it may be possible to step the nanoimprintsubstrate multiple times across the ophthalmic substrate to transfer theappropriate pattern.

As a non-limiting example a film of metal, typically comprising Gold,silver, platinum or copper or other metallic component or alloy may bedeposited upon the substrate with imprinted photoresist. A lift-offprocess may next remove metal and photoresist leaving a pattern ofnanostructured metallic features. Chemical cleans and physical polishingsteps may be useful to remove material remaining. A dielectric film maybe deposited upon the substrate, covering the metallic features and theregions lacking metallic features. Some of the metallic features may beused as electrodes for the EWOD cells to be built in other cases theymay be used to create the walls that surround each EWOD cell. Thedeposited dielectric film may be treated to condition its surface freeenergy. In a next step, the EWOD fluids may be added to the plurality ofcells created across the substrate. Next, a layer comprising the top ofthe EWOD cells may be placed upon the growing substrate structure.Electrical interconnects may have already been placed upon the top layerstructure for electrical connection.

At 1203, the resulting substrate structure may be transformed into athree dimensionally shaped structure. In some embodiments this may beperformed by thermoforming the substrate. The resulting threedimensional shape may become a part of an insert or may be an insert inits own right. It may be electrically connected to other componentswithin the insert as well. Next at 1204, an insert with the Nanoscalemetallic controlling features may be placed into a mold form. Theinsert, at 1205, may then be surrounded by ophthalmic material, whichmay be called reactive mixture, and encapsulated as ophthalmic materialmay be polymerized and shaped with the mold around the insert. Whenremoved from the mold a form of an ophthalmic device may be obtained. At1206, the resulting ophthalmic device may be measured for its opticalcharacteristics for example by a wave front aberrometer. The controlelectronics in the energized insert within the ophthalmic device mayallow for a test mode activation of the ophthalmic device and bothstates with Metasurface elements and without may be tested. Results fromthe measurement may be used to determine if the device thus formed isacceptable. Alternatively, at 1207 an alternative model may be formed byadjusting parameters in the modeling system based on the measuredresults. At 1208, these adjusted parameters and modeling characteristicsmay be feed back for refinement of the lens design.

There may also be methods for using an Ophthalmic device which has anenergized insert comprising Metasurface forming elements. In someembodiments, the Ophthalmic device may have two operational statesrelated to the Metasurface forming elements. In a first state when theMetasurface elements are activated, the lens may have a first effectivefocal characteristic and in the other state when the Metasurfaceelements are deactivated it may have a second focal characteristic.Thus, proceeding to FIG. 13, item 1300 a method for utilizing such anactive Ophthalmic device may be found. At 1301, an ophthalmic devicewith active Metasurface elements may be obtained. When the device is acontact lens embodiment, it may be placed in the user's eye region at1302. When settled in place, the user will observe the lens through hiseye to have a certain optical quality and characteristic. Next at 1303the user may provide an activation signal of some kind. This may entailsignals that the user may directly control, such as for exampleintentionally blinking his eyelids in some fashion. Alternatively,wireless communication devices may be controlled by the user to providea signal. The signal when received by the ophthalmic device may cause itto shift states. At 1304, the user may then observe the result of thestate shift through the ophthalmic device and recognize an alteredoptical quality and characteristic. In some embodiments, the user mayprovide a second activation signal at 1305 which may restore the activeOphthalmic device to the previous state it occupied prior to step 1303.The device may be removed from the eye at step 1306.

The invention claimed is:
 1. A method for forming a rigid insert for anophthalmic device comprising: depositing nanoscale metallic featuresonto a substrate to form a metasurface, wherein the nanoscale metallicfeatures have a surface area of less than or equal to 10,000 nm²;theroforming the substrate with the nanoscale metallic features into athree-dimensional form; and securing the three-dimensionallythermoformed substrate to an insert to form the rigid insert.
 2. Themethod according to claim 1 additionally comprising: designing theshapes and sizes of the nanoscale metallic features on a computerizedsystem comprising modeling software.
 3. The method according to claim 2additionally comprising: placing the rigid insert within a mold;surrounding the rigid insert with a reactive mixture in the mold; andpolymerizing the reactive mixture to form an ophthalmic device.
 4. Themethod according to claim 3 additionally comprising: measuring opticalcharacteristics of the ophthalmic device.
 5. The method according toclaim 4 additionally comprising: utilizing results obtained from themeasuring of the optical characteristics of the ophthalmic device toadjust a design process for the rigid insert.
 6. The method according toclaim 5 wherein parameters inputted into the modeling software come fromophthalmic measurements performed upon a patient.
 7. The methodaccording to claim 1 wherein: the nanoscale metallic features arearranged in a periodic pattern, the periodic pattern having aperiodicity of less than or equal to 700 nm.
 8. The method according toclaim 7, wherein the periodic pattern has a periodicity of greater thanor equal to 200 nm.
 9. The method according to claim 1, wherein themetasurface is configured to provide vision enhancement to an eye of apatient.
 10. The method according to claim 9, wherein the metasurfacealters the optical properties of the rigid insert in a non-radiallysymmetric manner.
 11. A method for forming an opthalmic device utilizingthe method according to claim 1 and additionally comprising: placing therigid insert within a mold; surrounding the rigid insert with a reactivemixture in the mold; and polymerizing the reactive mixture.
 12. A methodfor forming a rigid insert for an opthalmic device comprising:depositing nanoscale metallic features onto a three-dimensionallythermoformed substrate to form a metasurface, wherein the nanoscalemetallic features have a surface area of less than or equal to 10,000nm²; and securing the three-dimensionally thermoformed substrate to aninsert to form the rigid insert.
 13. The method according to claim 12,wherein the nanoscale metallic features are arranged in a periodicpattern, the periodic pattern having a periodicity of less than or equalto 700 nm.
 14. The method according to claim 13, wherein the periodicpattern has a periodicity greater than or equal to 200 nm.
 15. Themethod according to claim 12, wherein the metasurface is configured toprovide vision enhancement to an eye of a patient.
 16. The methodaccording to claim 15, wherein the metasurface alters the opticalproperties of the rigid insert in a non-radially symmetric manner.
 17. Amethod for forming an opthalmic device utilizing the method according toclaim 12 and additionally comprising: placing the rigid insert within amold; surrounding the rigid insert with a reactive mixture in the mold;and polymerizing the reactive mixture.